Rhodanese

Rhodanese, also known as rhodanase, thiosulfate sulfurtransferase, thiosulfate cyanide transsulfurase, and thiosulfate thiotransferase, is a mitochondrial enzyme that detoxifies cyanide (CN−) by converting it to thiocyanate (SCN−). Rhodanese, also known as rhodanase, thiosulfate sulfurtransferase, thiosulfate cyanide transsulfurase, and thiosulfate thiotransferase, is a mitochondrial enzyme that detoxifies cyanide (CN−) by converting it to thiocyanate (SCN−). This reaction takes place in two steps. The diagram on the right shows the crystallographically-determined structure of rhodanese. In the first step, thiosulfate is reduced by the thiol group on cysteine-247 1, to form a persulfide and a sulfite 2. In the second step, the persulfide reacts with cyanide to produce thiocyanate, re-generating the cysteine thiol 1. This reaction is important for the treatment of exposure to cyanide, since the thiocyanate formed is around 1 / 200 as toxic.:p. 15938 The use of thiosulfate solution as an antidote for cyanide poisoning is based on the activation of this enzymatic cycle.